About Ballistic

Ballistic is the definitive ballistics trajectory calculator for iOS devices, intended for serious shooters who want a serious (and seriously accurate) application. Ballistic calculates trajectory, windage, velocity, energy, lead, and bullet flight time for any valid range, and can compensate for atmospheric conditions such as temperature, barometric pressure, humidity, and altitude (it can also accept density of air or density altitute input). It's also much more than a basic trajectory calculator.
With a vast library of over 4,800 projectiles and factory loads, Mil-Dot and MOA rangefinder with head-up display capabilities, GPS and atmosphere awareness, full size charts, reloading companion, precision target log, and optional HUD for mounted firing, Ballistic is a complete precision marksman tool for hunting, at the range, or at home with your hand loads.

The world renowned JBM Ballistics computer is powering all of
Ballistic's computations. JBM is used by world-class shooters everywhere to
deliver some of the most precise calculations. This great ballistics
computer is now available in the palm of your hand and simpler to use than ever, and because it's fully integrated into Ballistic, you'll even be able to take JBM's extremely accurate calculations with you, even into areas with no cellular coverage.

Core Features

What other applications are still trying to copy...

An Expansive Ballistics Library
Select from a library of over 4,800 projectiles, factory loads, military loads, and performance data points from leading manufacturers, military testing, and performance testing - or specify your own projectile properties. Library includes the latest commercial data and several G7 military coefficients from Aberdeen Proving Grounds, as well as Bryan Litz' custom G7 BCs and projectile length data (AE and iPad editions only). Just select your bullet diameter and all of the available projectiles will appear, sorted by manufacturer. Auto-select the best factory load by wind drift, energy, or flatness. Ideal whether at the range, or comparing boxes of ammunition at the store.

JBM Ballistics Computer
The JBM Ballistics computer, written by James B. Millard, is among the world's finest ballistic engines in existence. Used by competition shooters, hunters, and the military, this powerful ballistics library delivers precision results. Results is what it's really about, isn't it? The JBM engine also adds new features such as velocity adjustments for chronograph, optimum point blank range, upwind (z-wind) correction, and midrange/downrange wind sources. When other ballistics applications look to measure their accuracy, they use the JBM engine as their gold standard - so why not just use a ballistics calculator that uses JBM?

In addition to the JBM ballistics engine, Ballistic also calculates gyroscopic spin drift, Coriolis acceleration, and Miller bullet stability. Bullet stability helps you determine if your barrel twist can support a projectile at a given velocity. With Ballistic's built-in reloading companion enabled, Ballistic will also calculate OGW (Optimal Game Weight), TKO (Taylor Knockout Factor) and IPSC PF.

One-Touch Atmosphere (tm) (Core Location)
Correct your calculations for the current atmosphere by pressing the Core Location button. Your altitude, standard pressure, temperature, relative humidity, and wind velocity will be automatically set based on your current location and information from one of three weather services (NMI, NOAA, and GeoNames). A global setting allows you to set which fields are updated. Manual entry can also be made.

When calculating Coriolis acceleration, the iPhone 3GS' built-in compass can automatically acquire your Azimuth to accurately calculate the correct adjustments for both windage and elevation.

Advanced Wind Kit (tm)(AE and iPad editions)
The Advanced Wind Kit (tm) allows users to easily and quickly program in even the most complex wind scenarios for up to eight wind sources. Simply tap to create a new wind zone and then slide it to the appropriate range. Pinch it to set a specific coverage for the wind zone, or leave it at a single range to create a range-wide linear band. Tap the dial icon to specify wind direction (or origin), wind velocity, and upwind velocity. The Advanced Wind Kit (tm) takes full advantage of the JBM ballistics engine's wind capabilities to allow pro shooters to account for nearly any possible wind scenario.

Print and Share
Print trajectory cards, ballistics charts, and your target log straight from your iDevice, in up to three sizes. Ideal for printing trajectory cards or full size trajectory pages. You can also share your data by sending it in an email.

Custom Projectiles, Bookmarks and Save State
Bookmark your favorite calculations and recall them later, or load them back into the ballistics calculator to tweak them or generate charts. Add notes to your bookmark to display underneath the bookmark title. Your bookmark will retain your ballistics information, zero, atmosphere, range, and all other data from your calculation.

Save custom projectiles with or without velocities into the ballistics library, for future recall in new calculations.

In addition to bookmarks, Ballistic can be configured to automatically save the last calculation in its active editor, and recall it the next time you start the application. Or leave auto-save turned off, and tweak the default values you'd like loaded whenever you use the application, such as zero range, wind velocity, and everything else.

Angle Acquisition
Aim the iPhone at the target like a remote control, or rest it on a cold barrel to acquire the line of sight angle for a more precise calculation.
A bubble level will appear show you your angle; simply tap to lock. You can also choose to use a three-second countdown to lock your angle.
The angle can also be inverted by 90° making it suitable for use in a weapons mount. The Head-Up Display (AE and iPad editions) can automatically lock onto your current angle and update your calculations in real-time.

Ballistics Charts
Ballistics charts allow you to display the energy, velocity, and drop for your current projectile, or compare up to eight projectiles together on the same screen. Your current atmosphere and zero are automatically applied to all projectiles, so you're comparing apples to apples. Compare bullet path and energy or wind drift. Ballistic will also show you trajectory charts based on altitude or shooting angle. Zoom up to 300% or save a full size chart to your photo library and transfer it to your desktop, print, or send a full size chart in an email.

Variable (Stepped) Ballistic Coefficients
Support for variable (stepped) ballistic coefficients for many popular projectiles including Sierra MatchKing®, GameKing®, and ProHunter®. Variable coefficients allow for more precise calculations and overall better accuracy by adjusting the bullet's flight to fit the commercial G1 drag model. Ballistic also supports all G1-G8 drag models. Custom projectiles with stepped BCs can also be created and saved.

Automatic Drag Model Conversions
Automatically convert between two different drag models. Ballistic will recalculate the ballistic coefficient and adjust its trajectory to fit the new drag model. This is ideal if you only have a G1 coefficient for a VLD, spire point, or other type of uniquely-shaped projectile, as it allows you to apply a more accurate drag calculation. This may improve your long range accuracy beyond that of the standard G1 calculation provided by the manufacturer. Wish your manufacturer produced stepped BCs? Convert the drag model to apply a more suitable drag.

Minimum, Maximum, and Optimum Point Blank Range
Ballistic automatically calculates your minimum and maximum point blank ranges based on your zero and the vital zone radius you specify, and will display these in the form of red arrows. The JBM engine can also calculate your optimum point blank range and will display this in each calculation. In addition to this, the sonic boundary will be marked with a yellow line.

Full Metric Support
Global settings exist to change the units of measurement for distance, atmosphere, and all other units. This includes bullet drop, altitude, sight height, wind speed, temperature, pressure, velocity, and energy. Favorites are automatically converted so that you can retain your zero and atmosphere, but appply the same calculations to either yards or meters. In other words, your favorite will stay zeroed at X yards, and give you accurate output for Y meters, and vice-versa.

Mil-Dot and MOA Rangefinder with Head-Up Display Option
Calculate distance using Mil-Dot or MOA reticles. Supports conversions including inches, cm, feet, yards, and meters. Supports both USMC and Army Mil-Dot specs. Includes on-screen dials for target speed, magnification, and with the iPhone 5 or iPad, on-screen windage controls. All other settings can be set from a menu. The head-up display comes standard with AE and iPad editions. With the head-up display, select a ballistics profile and display holdovers, elevation, and windage data in real time as you adjust it!

Precision Target Log with One-Touch Notes(tm)
Ballistic incorporates an advanced precision target log to keep a journal of all your hunts, shoots, adjustments, points of impact, and scores. Touch the Core Location button to automatically fill in your current coordinates, which you can later recall into the Maps application. Query a weather service for local atmospheric and weather conditions. Range log can automatically tally your target data cards and even keep track of your X's. Choose from a variety of targets or take a photo using your device's built-in camera. Different targets for zero data cards are also available. Use your zero data log enries as a source to set your calculations' zero atmosphere, or run scoring and cold barrel reports for each rifle.

The precision target tools turn your target log into a precision calculator and reporting tool. Place and measure true-to-scale points of impact and measure group size, exact placement, center offset, and much more.

Features:

Placement guides show you the precise distance offset to the nearest points of impact

Displays max/min group spread, distance to target center, group width/height,offsets to center, and more

"Group Analytics" range report, showing group size and min/max spread for all logs under any rifle!

Displays green crosshairs to mark center of group along with a grouping box and target center guide

Automatically scales the size of the impact markers based on the target scale and bullet caliber, for precise WYSIWYG editing

Can sync all of your data to iCloud. Seamlessly resizes to support both iPad and iPhone with the same target data

Reloading Companion
Reloaders can store their reloading information with each bookmark, including powder type and measure, COL, brass, and other information. Ballistic automatically calculates OGW (Optimal Game Weight) at both muzzle and zero, TKO (Taylor Knock-Out Factor), and IPSC Performance Factor.

New! Powder Sensitivity: Reloaders will appreciate this one. Added a powder "sensitivity" setting in the reloading section, allowing the user to define a velocity shift (per-degree) to adjust for powder temperature. When set, the muzzle velocity will automatically be adjusted using this value. The actual muzzle velocity will be displayed in the trajectory output; powder temperature is also taken into consideration when truing the velocity up. You'll need to have a zero and current atmosphere temp defined in order for the velocity to be adjusted.

Very fast and precise calculations, even at long range
Ballistic undergoes heavy testing and comparison with known data, and has satisfied many in accurately reflecting true-to-life trajectory. It compares very well to well respected ballistics packages such as Sierra's Infinity suite for the desktop. Whether you're using the JBM Ballistics computer or the original Ballistic engine, world-class results are what our world-class shooters are expecting - so we'd better deliver.

Skin and Color Scheme Support
Choose from many skins including Leather, Brushed Metal, and Gunmetal. Choose from color schemes including Red, Green, and Pink. Customize your user interface the way you like it.

New!iCloud Sync
The iCloud Sync feature can automatically synchronize your favorites and target log between devices, and even to other versions of Ballistic (3.5 and higher). Synchronize your iPad data with your iPhone or iPod Touch, and vice versa. Simply turn on the "Documents and Data" option for iCloud, then enable the "iCloud Sync" option in Ballistic's Settings. The target precision log automatically rescales your iPad data down to fit on your iPhone screen, or vice-versa.

Ballistic AE: Advanced Edition / Field Tactical

Ballistic AE is the advanced, field firing version of Ballistic, designed for advanced shooters, law enforcement and military personnel performing advanced and complex calculations, or field firing with
hardened, recoil-proof mounting equipment. The AE version of Ballistic includes all of the great features you'll find in the standard version of the software as well as the following advanced features:

Both versions of Ballistic share the same code base, and so identical version numbers will have all other identical code and features.

HUD Display

The HUD displays the range, wind velocity, and wind angle on click-wheel scroll pickers. Simply flick to the current settings and the trajectory will update. Turn on the LOS Angle switch for real-time angle locking.

HUD Settings

Select a ballistics profile from the HUD Settings screen. Choose a favorite or create your own custom projectile.

Advanced Wind Kit (tm)

The new Advanced Wind Kit (tm) in version 3 allows the user to quickly and easily create complex wind scenarios by configuring up to eight wind sources.

3D Trajectory Imaging

Generate a 3D visualization of the projectile's flight path, including both elevation and windage. Simply tap "3D Trajectory Imaging" underneath the Calculate button to generate.

Ballistic for iPad

The iPad provided an opportunity to completely redesign Ballistic's user interface for a larger screen. Available as a separate product in the App Store, Ballistic for iPad provides a beautiful, feature-rich user interface experience with the same great ballistics engine underneath.

Hints

Ballistic has many different settings including full metric support. Tap on Apple's "Settings" icon, then scroll down. You should see Ballistic near the bottom. Tap on it to bring up the application's settings.

Ballistic has three ballistics libraries: a projectile library, a loads library, and a custom library. Advanced and iPad editions also includes litz library. The projectiles library (and Litz library) is based on bullet diameter - not caliber, so remember that .223/5.56 projectiles are actually .224, .50 BMG is actually .51, and so on. Labels have been added to provide hints to popular bullet calibers, as shown in the screenshots. The loads library is based on caliber, and so you'll want to select the exact type of ammunition for your rifle. You'll find metric loads near the bottom. The library fills in the fields for ballistic coefficient(s), bullet weight, diameter, drag function, and (loads only) muzzle velocity.

If you're using the projectiles library, you'll need to supply the correct muzzle velocity corresponding to your ammunition. This is commonly found on the box or on the manufacturer's website or your reloading manual. Even though this information is provided for you, it's still a good idea to verify the data in the library with the information from the manufacturer. Please email us if there are any errors in either library (include the correct info and cite the source).

In the range log, double-tap the target to slide it to the bottom of the screen, increasing the size of the impact table. Tap the Target button to change the target. Double tap on an impact marker (the bullet hole) to toggle it between standard (black) and cold barrel (blue). Tap on an impact record in the impact table to bring up an action sheet with options. It's a good idea to record your cold barrel shots, so that you can run a cold barrel report at some point to get an idea of how your rifle shoots cold.

Wind angles work like this: 0° = headwind, 90° = crosswind (left to right), -90° = crosswind (right to left). You can use any angle, of course, not just these. You can also enter input in O'Clock format; e.g. 3:00 will automatically translate to 90°. Velocity will automatically be adjusted to account for the appropriate headwind calculation. To use O'Clock format in the HUD, set the windage dial format in Settings. The default wind input value is the wind direction (e.g. which way the wind is blowing). You can change this to wind origin in settings, if that's what you're used to.

Snap a screenshot of your Target Data card by pressing Home + Power together, then import it using the Image Capture Utility. To save a ballistics chart to your photo album, press Options followed by Save Chart. You can then use Apple's Image Capture Utility to import your photo library onto your Mac.

If you are zeroed in yards, but want distances in meters (or vice-versa), create a favorite containing your zero in the units you originally used. Switch over to the units you want your distance measured in by changing the global "Distance Units" setting. When you load back the favorite, your zero range will be automatically converted (e.g. 300 yard zero = 274.32 meters), and your output will be set for whatever unit of measurement you're currently using.

The "Desired Accuracy" GPS setting allows you to set the level of accuracy you're willing to settle for. As Core Location attempts to get a fix, its increasing level of accuracy will be reported back to the application. The higher you set the desired accuracy, the longer it will take for Core Location to get the fix you want. If the GPS can't give you the desired accuracy within the timeout period you specify, Ballistic will use the best fix it could obtain. This is only particularly important when calculating altitude, as your geographical coordinates only need to get you to the nearest weather observation. We currently have the settings tuned as follows:

Best - Altitude within 30 meters

Good - Altitude within 150 meters

Fair - Altitude within 300 meters

If you previously used the One-Touch Range Notes to fill in your current location, you can tap the "Location" cell to launch the Maps application with the current coordinates filled in. This is useful for finding that same hunting spot again. It also works if you just type in the location as an address or other place that Maps can identify, but using the one-touch feature will give you exact coordinates.

You can turn the "Wind Drift Chart" into a "Spin Drift Chart". Do this by setting the wind speed to zero, then load your favorites for comparison.

When entering Density / Mach data, you may enter the temperature in the Mach field and Ballistic will automatically calculate the speed of sound at this temperature.

The yellow band in the trajectory output indicates the sound barrier; it's where your bullet falls from supersonic into subsonic. This is typically where your bullet can begin to tumble.

The red arrows indicate your point blank range, based on your vital zone radius. For your current zero, you can shoot within these ranges and be +/- your radius without any scope adjustments.

FAQ

Do you plan to make Ballistic available on Android / Blackberry / Windows / etc?
We don't have any current plans to expand Ballistic beyond iOS. Sorry.

Will this run on my [Dell Axiom, Windows Phone, Newton Message Pad] non-iOS device?
Ballistic ONLY runs on iOS devices. This includes iPhone, iPod Touch, and iPad. Ballistic will NOT run on PocketPC devices, Windows phones, Android phones, or anything that is not running Apple's iOS operating system. Sorry.

Is there a manual?
This website contains a lot of instruction about how to use Ballistic and the various settings. For everything else, most of the technical questions we receive about Ballistic fall into one of two categories: questions about the user interface, and questions about ballistics in general. Regarding the former, Apple has developed a standard set of user interfaces and recommends you learn them, so that each piece of Apple software does not require its own manual. The goal is to make Ballistic as user friendly as possible, and to conform to Apple's user interface standards, so that it can be used without reading a book first. The more familiar you become with your device, the more familiar you'll become using Ballistic. With that said, we've documented all of the terms and settings on this website that are used in the application.

Regarding questions about ballistics in general, you might consider picking up a copy of Sierra's reloading guide, which comes with a section on external ballistics, or pick up a copy of Bryan Litz' "Applied Ballistics: 2nd Edition". You can't cover how ballistics works in a manual. Given that, we have provided a lot of basic information on the website here. If you can't figure something out, please feel free to email us after you've read through the information on this website.

Does the ballistics library have my favorite brand?
Ballistic includes a library of over 4,800 projectiles, factory loads, military loads, and professional measurements. The library is always growing, but if you can't find your favorite brand, you may input your load's ballistic coefficient and muzzle velocity manually. This information can usually be found on the manufacturer's website or by calling them. If your favorite manufacturer publishes their ballistic coefficients (and muzzle velocities, if they're loads), send us link and we'll try to add it to our database.

Does the ballistics engine work without cellular coverage?
Yes. The ballistics engine is compiled into the application so it does not need Internet access. You can even perform calculations on your iPod touch with no Internet. What you will need Internet access for, however, is if you want to download up-to-date weather station information from a weather service. Don't worry, though, you can always enter it in manually if you're shooting in an area with no coverage.

What is your relationship with the author of JBM Ballistics?
We licensed the JBM ballistics engine after using it extensively for years. We initially designed this app for ourselves (after wasting money on other ballistics calculators in the App Store, only to be disappointed), and wanted the most powerful and accurate ballistics engine powering it. Even though the app uses the JBM ballistics engine, please make sure to contact us directly for support as JBM won't be able to help answer your questions. Thanks.

Are your calculations the same as everyone else's?
Most ballistics computers (including Ballistic) use well established mathematical formulas used for over one hundred years. The mathematics were well documented by Sierra's ballistics laboratory, based on calculations used by the US Army Ballistic Research Laboratories at Aberdeen Proving Grounds. These calculations are used in Ballistic as well. 3-DOF calculations for trajectory, atmospheric correction, etc., are typically very similar between software packages, and should provide similar results.

While all results are similar, precision is pretty important when it comes to a good ballistics calculator. That's the main reason Ballistic now uses the acclaimed JBM ballistics engine and why we decided not to use one of the free but much less accurate and less feature rich open source libraries (like the one that the Direkon engine is based on). One area where Ballistic is more accurate than many is in its ability to account for a number of advanced factors, such as gyroscopic spin drift, Coriolis acceleration, atmospheric zero conditions, and in its ability to handle things like stepped ballistic coefficients (such as those published by Sierra) and complex wind configurations. Support for these is very important, as it allows Ballistic to fine-tune its physics to your environment, to give you results that work in the field, as opposed to in a lab. Ballistic is also capable of handling G1-G8 drag models, allowing for more accurate results when calculating bullets such as spire points, VLDs, and military bullets. Don't settle for a ballistics program that handles only G1 - it was made for bullets that existed over a hundred years ago, and doesn't accurately calculate today's more flat-base projectiles. The projectile library contains G7 and G8 data for all its military projectiles rated at Aberdeen Proving Grounds and can handle any G1-G8 coefficient you provide. It can also perform real-time conversions between drag models if you'd like to convert a commercial coefficient to a more suitable one. Finally, if you're looking to squeeze every last bit of accuracy out of your rifle, Ballistic includes a library of Bryan Litz' G7 BCs for many popular projectiles, which more closely reflect the actual accuracy of a bullet, rather than its advertised accuracy.

With that said, the JBM ballistics engine is far superior to its competitors in that, in addition to basic 3-DOF calculations, JBM's sophisticated engine is capable of accounting for advanced calculations including linear wind calculations (and calculations from more than one wind zone), better atmospheric density equations, and incorporates more advanced physics in its computer. If Ballistic can get even a couple inches tigher at 1,000 yards, then that's significant in real-life application. Rather than trust some home grown ballistics engine to be written correctly, trust one that's already used by top shooters. Nearly every application out there measures their accuracy based on how close it comes to JBM... so why not just use an application that runs the JBM engine?

How do I add a favorite?
First, calculate a trajectory. When the trajectory results appear, tap the plus sign on the upper-right of the screen to add it as a favorite.

Where can I find the settings?
You can access them by going to the Settings app on your iPhone or iPad:

Scroll to the bottom. If you didn't know that, you might be pleasantly surprised to find that many of your other installed applications may also have a section at the bottom.

How can I get tenths or hundredths in the HUD?
Go into the the Settings app on your phone, scroll down to select Ballistic, then change the "Output Precision" in the "Head-Up Display" section from "Whole Number" to either "Tenths" or "Hundredths".

I change the settings, but the app still uses my old settings.
Most settings can be changed without restarting Ballistic, but some do require that you restart it. To force-quit Ballistic, go to the home screen. Double tap the home button, swipe left until you see Ballistic, then flick it upwards like you're trying to flick it off the screen which will exit the app. You can also simply restart your phone. This can also occur if you've set application defaults. For example, if you've changed your default atmosphere type to use Density Altitude, but are still seeing meteorological fields, you likely saved the meteorological data with your defaults. Tap on the action icon and "Reset Defaults" after you've made such changes, and this should update your data input.

Can I Enter Density Altitude or Density of Air?
Yes! You can change your atmosphere format to either of these. Go into Settings, and then select the Atmosphere option.
NOTE: If you saved custom defaults, or are using 'Save State', you'll need to 'Reset Defaults' after you change default atmospheres. Otherwise, the old atmosphere from the default will be loaded.

How can I set new application defaults?
Tap on the action icon in the upper-left hand corner of the Trajectory screen, and select "Save Defaults". Whatever values you have plugged in will become your application defaults. To reset them to factory, select "Reset Defaults". You can also turn on auto-save to save your last calculation.

How can I compare Ballistic with other programs?
When comparing Ballistic to something else, keep in mind that many packages use different defaults or even different atmospheric measurements, so you might need to do some tweaking to compare apples to apples. Make sure both packages are set to the same zero, sight height, and especially the same atmosphere. Ballistic uses the ICAO atmospheric model, while others (such as Perry-Systems' ExBal) use the US Army standard. Be sure to enter one or the other pressure manually into both packages to compare apples to apples. The default atmosphere used by Ballistic is sea level with 29.92 Hg., 59 °F, 78% humidity. Be sure your comparison calculations match these (some packages use 0% humidity, or other default values). Finally, enter ballistic coefficients by hand rather than relying on each package's library for your testing, as they might each use different values.

You should be able to successfully compare Ballistic to JBM and get identical results. Do this by starting with Ballistic's factory defaults (use "Reset Defaults" if necessary). Now, set a muzzle velocity of 3000 fps, then create a constant, 10mph wind stretched from 0-1000 yards (or "muzzle", if using simple wind), 90 degrees. These settings should perfectly match JBM's defaults and give you 294.6" of drop at 1000 yards, and 82.6" of wind drift.

Should I mount my iPhone/iPod on my rifle?
If you want... but not without a military-approved recoil-proof mount. The iPhone is not recoil rated in and of itself, so unless your manufacturer is going to guarantee that the device will not be damaged, and is willing to back up that claim by buying you a new one, you could cause irreparable damage to the device. Unless you have such a guaranteed mount, we recommend that you remove your iPhone or iPod from the rifle before actually firing. We've busted "military grade" scopes, levels, lasers, and other equipment from the recoil on our rifles - don't take the amount of force for granted; it can damage your iPhone without a properly designed case.

How can I calculate drop from barrel, rather than from a zero?
Set both your "Sight Height" and "Zero Range" to zero values.

Why did you write this?
As avid shooters, we got sick of printing and memorizing trajectory cards for every load we fired. The iPhone is the ideal device for calculating real-time ballistics given its GPS, accelerometer, and network connectivity. We wanted a tool that could immediately adjust our calculations for the current weather conditions, altitude we were shooting at, and convert between yards/meters depending on what range we were using. We gave a different iPhone application a try and decided that iPhone users deserved better. It works well and we take pride in making Ballistic the best mobile ballistics computer on the market, if anything for our own personal enjoyment.

List of Terms

The following terms are used as input when providing data on the trajectory screen. Some are also used in the HUD. Many of the more advanced terms can be turned off when putting the application into "Simple Mode" in settings. Here's a list of what each option does.

Ballistic Coefficient (BC): Typically obtained from the manufacturer, this value represents the ratio of drag for a given bullet. The ballistics library contains ballistic coefficients for thousands of different projectiles, but if you don't find yours there, contact your manufacturer for this number. To access the ballistics library, tap the blue disclosure to the right of the Ballistic Coefficient field.

Bullet Diameter: The actual diameter of the bullet in inches.
Not caliber. This value is used primarily for informational purposes, as this information is already considered in the ballistic coefficient. You'll need to know the correct diameter if choosing a bullet from the projectiles library. The loads library is, however, sorted by caliber, allowing you to choose your particular cartridge type without knowing the diameter.

Bullet Weight: The weight of the bullet in grains (7000 grains is equal to one pound). This is used primarily for informational purposes, as this information is already considered in the ballistic coefficient. It is filled in when you select a projectile or load from the ballistics library.

Native Drag Model: A ballistic coefficient's value is based on a specific drag model; e.g. G1, G7, etc. The drag model that goes with the supplied BC is the native drag model. Most manufacturers provide BCs with a G1 native drag model, however some are finally publishing G7 drag models as well. Be sure that the drag model you specify matches the one that the manufacturer used in publishing the ballistic coefficient, otherwise the calculation will be off.

Muzzle Velocity: The velocity of the bullet as it leaves the muzzle of your rifle. Most manufacturers print average velocities on their boxes, or provide this information on their website. For more accurate results, you might consider using a chronograph to measure actual velocity. Velocity can change by a number of factors including barrel length, temperature, and even the amount of fouling in your rifle barrel, so if you're serious about pin-point accuracy, you should invest in a good chronograph and practice consistent barrel cleaning after each shoot.

Chronograph: Velocity usually isn't measured right at the muzzle, but rather by a chronograph placed a number of feet in front of the muzzle. As a result, the actual muzzle velocity may be slightly higher than that recorded by the chronograph. By entering the chronograph's distance from the muzzle in this field, Ballistic will calculate the actual muzzle velocity from the velocity you provided and the distance supplied in this field. If you are measuring velocity right at the muzzle, set this value to zero.

Use Drag Model: One of Ballistic's more advanced features is to allow you to seamlessly convert from one drag model to another. If you would like to convert this projectile's BC to fit some other drag model, choose the drag model you'd like to convert it to here. The BC will be adjusted based on the drag model selected and the given muzzle velocity.

Zero Range: The range at which the rifle is zeroed at, with the given ammunition. It is expected that the rifle's point of impact will match the rifle's line of sight at this range, at zero angle.

Sight Height: The distance between the centerline of the barrel and the center of the scope or sight. This is very important, as the bullet's drop will begin at this distance out of the muzzle.

LOS Angle: Line of sight angle (your shooting angle). This is the angle at which your rifle is aimed. A value from -90 to +90 is acceptable here. The shooting angle dramatically changes the gravitational effect of the bullet, ultimately changing your trajectory. If shooting straight, leave this value at zero.

Zero Atmosphere: The climate and altitude at which you zeroed the rifle at. Pressure, humidity, and other factors can affect the density of air, which affected how the bullet traveled when you zeroed the rifle. When this is disabled (default), no corrections are made to account for this. If you have this information available, however, it will allow you to fine-tune the output to account for zeroing in one climate and altitude (e.g. summer, at 300 ft above sea level) and shooting in another (e.g. winter, at sea level).

Current Atmosphere: The current climate and altitude you are shooting at. Pressure, humidity, and other factors can affect the density of air, ultimately affecting the amount of drag on the bullet. By specifying a current atmosphere, Ballistic adjusts the BC of the bullet to compensate for this. Leaving this option disabled will cause Ballistic to forego any corrections.

Pressure is Absolute: If the pressure being provided is the absolute pressure given elevation, turn this switch on. If the pressure needs to be corrected (e.g. if it is a station pressure, reported elsewhere), leave it off.

Wind Velocity: The speed of the wind. This is used to account for windage (in crosswinds) and also adjust the bullet's velocity (in headwinds).

Upwind Velocity: Vertical wind. If your range has upwind flags, you can enter the estimated speed of the wind traveling upward (or downward) into this field, and your elevation will be adjusted to compensate.

Wind Angle: The angle of the wind direction. Changing this value can affect both windage and trajectory by a factor of the wind speed. By default, the wind angle indicates the direction of the wind, however you can change this in settings to make it reflect the origin of the wind.

Wind Position: The position at which the strongest wind is crossing; by default, this is set to "Muzzle", but can also be set to "Midrange" or "Downrange". Ballistic will adjust your windage (and elevation, if an upwind is specified) based on where the wind is strongest. This option is only used when using simple wind. When using the advanced wind kit, you can specify the exact position of the wind in a number of scenarios.

Maximum Range: The maximum range to be calculated and displayed in both the trajectory calculations and charts. NOTE: If you put a minus sign before the range (e.g. -1000), the calculation will show only that specific range.

Minimum Range: The minimum range to be displayed in the trajectory calculation. This is useful if you are displaying a lot of data, and want to focus on a particular set of distances.

Range Increment: The increment (step) to be used in displaying the calculated trajectory. E.g., every 25 yards.

Vital Zone Radius: The size of the vital "kill zone" of the target, used to calculate point blank range. For example, if your vital zone radius is 5 inches, your point blank range will span from your zero to the lowest and
highest ranges at which you can hit the target inside that radius.

Elevation / Windage Units: The units in which to display elevation and windage. This can be MOA, MIL, or a number of other values including a custom click value.

Elevation / Windage Turret Value: Some scopes are not exact; that is, one click does not necessarily equal exactly one MOA or one Mil. If you know the actual click value of your scope turrets (for example .982), you can enter it here. The output units (regardless of whether they're MOA, mRad, or anything else) will automatically be divided by this value, to give you an accurate number of clicks. For example, if your turret value is 1/3 of a click and your output is 5 MOA, then enter .333 in this field. The output will read 15.01 (5 / .333).
NOTE: Versions < 4.7 multiply this value, rather than divide it. Division is the correct way to compensate for turret correction, so if you're using an older version below 4.7, you'd enter 3.333 instead of .333.

Zero Height / Zero Offset: The height and offset of the zero point at the zero range. For example, if your zero is 100 yards, and you want to assume the bullet travels 10" above zero at 100 yards, you'd set the zero height value to 10. If you want the bullet to be 6" offset horizontally at your zero, set the zero offset.

Windage is Zeroed: When calculating spin drift, enabling this option will tell the application that you've zeroed your windage at your zero range. This is particularly useful if calculating spin drift without wind.

Miller Stability: This is a bullet stability calculation, used to determine if your barrel twist can stabilize a given projectile. Stable values range from 1.4 to 2.0.

Application Settings

Ballistic is an extremely customizable application, and has a number of different settings available. To change your application settings, go into Apple's "Settings" application and scroll down to the bottom. You'll see an icon for the Ballistic application. Tap that icon to access these settings. NOTE: The very first group of settings ("General Settings") require you to force-quit the application in order to take effect. To force quit the application, press the home button twice to bring up the recents list across the bottom of the screen, then press and hold the Ballistic icon until a red minus sign appears. Tap the red button to force quit the application.

General Setttings

Open With: Allows you to choose which tab you'd like the application to open with. The default is Trajectory.

Skin: Choose from a selection of custom skins for the application. These include a default light / dark skin, as well as graphic skins including leather, brushed metal, and gunmetal.

Color Scheme: Choose the color scheme for text displayed in the application. These include default light / dark colors, as well as tactical red, tactical green, and tactical pink.

General Behavior

Print Size: Allows you to choose the size at which to print trajectory charts. Using the smaller print sizes allows you to print small trajectory cards straight from the application, while the large size allows you to print a full size trajectory page.

Save State: If you would like Ballistic to automatically save the state of the application so that your trajectory defaults will match the last calculation you ran, turn this feature on. When off, the application will always start up with the last saved defaults you specified.

Custom Velocities: When saving custom projectiles to the projectiles database, turning this feature on will also cause the velocity to be saved.

Sync with iCloud: When on, syncs favorites and precision target log entries with your iCloud account, and with other copies of Ballistic connected to the same iCloud account. NOTE: Documents and Settings must be turned on in order to sync data.

Units of Measurement

Distance Units, Atmospheric Units, All Other Units: These three options allow you to enable metric units for various portions of data within the application. Rather than having to change around units for every single field, you can simply specify imperial or metric units for these three categories and Ballistic will do the rest.

Mil-Dot Spec: Allows you to specify the Mil-Dot Spec (USMC or Army), and will use the appropriate mil-dot values in distance calculations.

Reticle Type: The type of reticle to display when using rangefinding features. Options include open or closed Mil-Dot and MOA.

Invert Angle 90: If you are mounting your device to a rifle using an Otterbox or other case, this setting may be used to cause the angle to read out from the middle of the back of the device, rather than the default, which is from the top of the device (like a remote control). This way, when the device is facing you standing up (perfectly level), the angle will read zero, and as you tilt the rifle up or down, the angle will read correctly.

Level: This option enables the built-in level within the application, which appears when you tap on the LOS Angle field. If you don't wish to use the level, turn this feature off and you'll instead hear three beeps prior to locking onto an angle.

Angle Calibration: Used to calibrate the accelerometer. This value will be added to the existing calculated angle. You'll only need to tweak this if your device is wonky, and doesn't read zero when perfectly level.

Trajectory

Ballistics Computer: The ballistics computer you wish to use. JBM is the default, and it is strongly recommended that you use the JBM computer for the best accuracy possible. The legacy Ballistic engine is also available, and yields results similar to the popular Direkon ballistics engine, however lacks many of the advanced features JBM offers.

Output Precision: Controls how many digits to round the trajectory output to. The default is hundredths, however as many other ballistics computers round to tenths, this option is also available.

Calculate on Launch: (iPad Only) Specifies whether the application should automatically calculate a trajectory on the split-screen, when the application is first launched. If turned off, the application will wait for the user to tap the calculate button.

Automatically Recalculate: (iPad Only) Specifies whether to automatically recalculate the trajectory on the split-screen, whenever the user changes any values on the left. If turned off, the application will wait for the user to tap the calculate button.

Show Variable BC On by default, this option controls whether to display (in the trajectory output) all of the different velocities and BCs that comprise a variable BC when used.

Atmosphere: Controls whether to load the zero and/or current atmosphere from favorites / defaults. It can be useful to tell Ballistic to retain the current atmosphere if you want to keep the atmosphere you acquire at the range, rather than load a new one every time you load a favorite.

Atmosphere Format Allows you to specity the kind of atmosphere data you want to provide the application: Meteorological, Density of Air, or Density Altitude.Calculate Max PBR Zero: Causes the max point blank range zero to be calculated and displayed with the output.

Hide Fields A separate menu allowing you to choose which (unused) fields to hide from the trajectory screen.

3D Trajectory Imaging: (AE and iPad Only)

3D Render Colors The color scheme to use to render 3D

Full Screen Imaging (iPad Only) When on, imaging is rendered full-screen. When off, imaging is rendered in the trajectory output window.

Wind Instrumentation:

Simple Wind: If you prefer not to use the advanced wind kit, specifying simple wind will give you a simple wind dial and wind speed entry. Simple wind is the default on the standard edition if you have not upgraded to the advanced wind kit. Simple wind is also used in the HUD so that the wind speed and angle dials can be used.

Wind Value: Specifies whether the wind angle you specify is the direction of the wind, or the origin of the wind, depending on what you're used to.

Windage: Specifies whether a right wind value should be positive (default) or negative, depending on what you're used to.

Reloading

Display in Output: If you would like your load data incorporated in the trajectory output, turn this feature on.

Range Log

Extended Log: Causes the range log to include velocity and notes with each point of impact. Ideal if using a chronograph. This also activates a number of grouping calculations to calculation average velocity and min/max/avg chrono spread.

Range Reports: Displays range reports options under each rifle in the range log. These include a cold barrel report and a rifle scorecard, which use the data inputted in your target data to create performance reports.

Line Thickness: (iPad Only) Specifies the line thickness for all chartlines. The default is thin.

Head-Up Display (AE and iPad Only)

Angle Threshold: The amount of change to your shooting angle before the HUD will lock onto the new angle

Beep on Lock: Whether to beep when a new angle is locked.

Large Readout: On by default, this option hides the drop (inches/cm) and displays only elevation/windage units in a larger display. To display both units and inches/cm, turn this option off.

Show Come-Ups: On by default, this option displays U/D L/R comeups instead of positive/negative drop/windage values.

Display Lead: When on, a fourth "Lead" dial is added to the HUD, displaying target speed to calculate lead. The lead is added to the windage output.

Output Precision: Determines the precision to which the elevation and windage are rounded. The default is whole numbers. Other valid options are tenths and hundredths.

Zero Range: Whether to load the zero range from your profile, or to use the zero you supply in the HUD settings

Angle Dial Format: Specifies whether the angle dial in the HUD should read in degrees or o'clock format.

Core Location

Desired Accuracy: Sets the accuracy required in order to obtain a GPS lock. Using higher accuracy causes longer delays in obtaining a GPS lock. "Good" is the default.

Weather Service: Specifies the weather service to use for weather data. The default is NMI (Norway Meteorological Institute), which is by far the quickest and most accurate service of the three. NOAA and GeoNames are also available options. When using NMI, your altitude is determined from topological maps. When using NOAA, Ballistic will attempt to obtain your altitude from the GPS (which can sometimes be inaccurate), before it will attempt to obtain it from a toplogical map.

GPS Timeout: How long to wait for the desired accuracy in obtaining a GPS lock

Update Fields: A list of fields to update with weather information when downloaded.